A variety of processing apparatuses such as a heat treating apparatus, a film forming apparatus, an etching apparatus, and so forth are disposed in a semiconductor manufacturing factory. Since various kinds of processing gases are used in these processing apparatuses, disposed in the factory is a gas supplying apparatus for supplying the processing gases stored in gas cylinders, i.e., processing gas supply sources, into the processing apparatuses via gas pipes. Further, in place of the gas cylinders, a gas generating device equipped with an electrolytic cell may be used as a processing gas supply source (see, for example, Patent Reference 1: Japanese Patent Laid-open Application No. 2004-169123).
The gas pipe of the gas supplying apparatus is connected to a gas box installed in each processing apparatus. When necessary, the gas box opens a gas inlet valve to introduce a processing gas from the gas pipe of the gas supplying apparatus and then supplies the processing gas into a processing chamber of the processing apparatus while controlling a flow rate of the processing gas via a flow rate controller such as a mass flow controller (MFC) or the like.
Conventionally, while the gas supplying apparatus is under operation, the gas pipe of the gas supplying apparatus is always maintained charged with a processing gas so that the processing gas is ready to be used at any time, except for exceptional occasions that a gas cylinder is being replaced (see, for example, Patent Reference 2: Japanese Patent Laid-open Application No. 2003-14193) or a gas leakage takes place. Accordingly, when the processing apparatus needs to use the processing gas, the processing gas can be immediately introduced into the processing chamber by opening the gas inlet valve of the gas box, thus carrying out a desired process on, for example, a wafer.
Moreover, if the wafer process by the processing apparatus is completed, the gas inlet valve of the gas box is closed to stop the supply of the processing gas. Then, after performing loading/unloading of the wafer and/or adjustment of inner condition of the processing chamber, the gas inlet valve of the gas box is opened again so that the processing gas is introduced into the processing chamber.